Glaucoma is one of the leading causes of blindness in the United States. In whites it ranks third behind retinal diseases and cataract with an estimataed blindness prevalence of 8.6/100,000. In blacks, it is the leading cause of blindness with a blindness prevalence of 72.0/100,000, a seven-fold excess over whites. The general objective of this project is to determine the source of this greatly increased prevalence of glaucomatous blinding in blacks. This study will measure the prevalence of glaucomatous visual field loss and ocular hypertension in comparable populations of whites and blacks in East Baltimore and, based on the cases ascertained in the prevalence survey, compare the potential risk factors between cases and controls stratified by race. A two-stage probability sample of households in East Baltimore will be selected and all persons residing in those households who are 40 years of age or older will be screened for visual field loss and elevated intra-ocular pressure at neighborhood screening centers. Those who test positively for visual field loss, elevated intraocular pressure, unexplained reduction in visual acuity, and a sample of normal will be evaluated at the Wilmer Eye Institute to further define their diagnosis and to confirm the screening results. Sources of data for this study will include both screening and evaluation examinations, anthropometry, blood pressure, and a personal interview. In addition, the families of a sample of cases and controls will be examined at the Wilmer Institute to investigate the role of familial factors in chronic open angle glaucoma.